Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
The semiconductor industry continues to improve the integration density of various circuit components (e.g., conductive lines, transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. However, as integration density increases, adjacent circuit components are spaced closer together and this can result in parasitic capacitive coupling between adjacent circuit components, which in turn can lead to several disadvantages.
One disadvantage is cross-talk or electromagnetic interference between adjacent circuit components. For example, a signal present on a metallization line may interfere with another signal present on an adjacent metallization line. Another disadvantage associated with close proximity of circuit components is the potential increased signal delay (e.g. RC delay) and reduction in frequency bandwidth. For example, the presence of a grounded metallization layer in proximity to a metallization layer carrying a signal may decrease the signal propagation speed leading to possible delay errors. Also, a grounded layer that is in close proximity may reduce the frequency bandwidth of the signal on an adjacent metallization line.